DPL is a script that allows for the creation of lists of pages using various criteria. For our purposes we will strictly be using it as a replacement for the categories intersection function to search for pages that belong to certain categories. This can be very useful for content revisions and making versus threads.
Inserting DPL code into any regular page is strictly forbidden. It should only be used in a single specific personal sandbox page for every member that needs to use it for some reasonably important category intersection purpose.
For example, if you want to find a list of all characters that are Tier 8 in the Naruto verse, you can use the following code:
<DPL> category = Naruto category = Tier 8 </DPL>
The above example categories should obviously be replaced by the ones suited to your intentions.
For further information click here.